Adding Google benchmarking library.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index cf3d3058900bf362101f226b7a18e705f50b1572..5ce1c21966172f1fbebc9131d9bfb36fa77f4e8d 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1743,6 +1743,7 @@ test("base_perftests") {
     "message_loop/message_pump_perftest.cc",
 
     # "test/run_all_unittests.cc",
+    "containers/containers_benchmarks.cc",
     "json/json_perftest.cc",
     "threading/thread_perftest.cc",
   ]
@@ -1902,6 +1903,17 @@ if (is_ios || is_mac) {
   }
 }
 
+test("base_microbenchmarks") {
+    sources = [
+      "containers/containers_benchmarks.cc",
+      "test/run_all_base_microbenchmarks.cc",
+    ]
+
+    deps = [
+      "//third_party/google_benchmark",
+    ]
+}
+
 test("base_unittests") {
   sources = [
     "allocator/allocator_interception_mac_unittest.mm",